TELL(3C) Standard C Library Functions TELL(3C)

tell - return a file offset for a file descriptor

#include <unistd.h>
off_t tell(int fd);

The tell() function obtains the current value of the file-position indicator for the file descriptor fd.

Upon successful completion, tell() returns the current value of the file-position indicator for fd measured in bytes from the beginning of the file.

Otherwise, it returns −1 and sets errno to indicate the error.

The tell() function will fail if:

EBADF

The file descriptor fd is not an open file descriptor.

EOVERFLOW

The current file offset cannot be represented correctly in an object of type off_t.

ESPIPE

The file descriptor fd is associated with a pipe or FIFO.

The tell() function is equivalent to lseek(fd, 0, SEEK_CUR).

See attributes(7) for descriptions of the following attributes:

ATTRIBUTE TYPE ATTRIBUTE VALUE
MT-Level MT-Safe

lseek(2), attributes(7)

January 28, 1998 OmniOS